Boiler-furnace.



M. W. SEWALL.

BOILER FURNACE.

APPLICATION FILED MAR. 12, 1910.

2 SHEETS-SHEET 1.

6% AU N Eh Patented Nov. 7, 1911.

M. W. SEWALL.

BOILER FURNACE.

APPLICATION FILED MAR. 12, 1910v Patented Nov. "2", 1911.

2 SHEETS-*SHBET Z.

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INVENTOR /ZZMM if. M

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$ ATTORNEY! WETNESSES:

. the space below the 'inches'below the leve of the grate surface "a fire brick lining to the walls'is commenced features to the life of the life.

warren s raws regatta craves.

MINOTT W. SEWALL, OF NEW YORK, N. Y., ASSIGNDR TO THE BABCOCK 6c WILCOX COM- PANY, OF BAYONNE, NEXV JERSEY. A CORPORATION OF NEVJ JERSEY.

BOILER-E URNACE.

Specification of Letters Patent.

Patented Nov. 7, 1911.

Application filed March 12. 1910. Serial No. 548,821.

To all whom it may concern:

' Be it known that 1', Mixo'r'r V. Sewann, a citizen of the United States, residing in the borough of Manhattan. citv of New 'York, in the county of New York and State of New York, have lnvented certain new and useful Improvements in BoilcrFurna'ces, of which the following is a spccifi-- cation,

The usual methods of building and 111- casing brickwork for a boiler and furnace to build up the walls from the floor line of the boiler room. The lower portion of these-walls serves to inclose the ash pit or rate surface.

which lining extends throughout the furnace and-the greater portion of the interior of the side walls of the boiler. Fire brick arches are in some cases used over a portion, and in other cases over all of the grate area. Infact, the whole interior of a boiler furnace consists of fire brick walls and arches. A furnace well inclosed by fire brick surfaces is the most efficient furnace for the combustion of coal, and great pains have been taken :to constru'ct furnaces in such a manner that fire bric surfaces shall cover the fuel .bcd, or shall form a roof over the fuel bed. The fac't that furnaces are thor oughly inclosed in fire brick surfaces is, notwithstanding its value for the processes of combustion, one of the most detrimental gurnace. This is because such a furnace pro uces an exceedingly high temperature. The higher the temperature, the more perfect will he the combustion. On the other hand, the high temperature is exceedingly destructive to the furnace Walls and such furnaces as have been described have a comparatively short The'object of this invent-ion is to produce a furnace that will give results as nearly possible to that of the inclosed fir'e brick furnace and at the same time have a much greater length offlifel, also onethat, when: necessity-requires, may: be repaired at low A few other cause of failure is the adhesion to the furnace walls of clinker formed ncar the grate'and of dust, that arises from the fire, adhering to the hot surfaces and becoming vitrified upon them and thusbuilding up large masses of clinker which must later beair to the furnace, which is in itself detri-.

mental bothto the life of the furnace and the ciliciency of the boiler.

According to the present invention the furnace walls begin at the grate line rather than at the floor line. One of the advantages of this construction is that with the use of chain grate stokers ample air ducts inay be introduced into the space ordinarily occupied by the walls and in cases where air ducts for forced blastaie not required the space is very advantageous in obtaining access to the sides of the stoker for observation or for repairs. The usual custom is to build chain grates so that they may be moved out from under the boiler altogether for purposes of repair. The large floor area that is required, however, for this purpose becomes very expensive for large boiler installations and it is very desirable that it. be not required to draw the stokcrs out more. than a few feet, and in such cases access to the sides of the stokcrs, although not absolutely necessary, is a great advantage in operation.

In the accompanying drawings which illustrate one form of my invention Figure l is a vertical longitudinal section through the furnace andgboilen; Fig. 2 a scctiop on .the plane of the line 22 of Fig. 1 with the bridge wall rerriovel; Fig. 3 a. section on the plane of the lineii 3 of Fig. 1; Fig. 4 a section on the plane of the line 4-4 of Fig. 3; and Fig. I) a cross section of a modification.

Similar reference numerals indicate similar parts in the several views they-have heretofore takenacross the uptake end of-the bank of tubes. \Vith such construction I can, with highly volatile grades of bituminous-coal, hold the flame substantially back from going among the tubes and "still maintain the accustomedsteaming I -capacity and 'efliciency ofthe boiler-substantiall without smokm and the nuisance inci ent thereto; Int is construction the first ."horizontally' and then the upper por A, B and; C,Vthe grate being 'locat bank of inclined water tubes 1 is divided asses subtion is divided into three transverse sta ntially beneath the first pass A and the gases compelled to travel: upward across tubes 8, then back over the bridge wall 2,

and thence'forward through the passage 3 formed by-the-baflies 4 and 4; to the first pass A at the steam uptake end of the boiler. The battle 4" extends" firom' the-rear header 6 1 forward"; to the' foot of thebafiie 7 which separatesthe first pass A from the second" pass B and is supported on an intermediate row 'of the bank of inclined tubes 1.: The

' bafllefiextends from the bridge wall toward 7 the-frontqof-the furnace; and the bafiie:. 4=,

extendsbeneath the first 'and second passes,

"and 'is supported by the lower water tubes: ,ofbank 1 which are embedded a part of ;'their length in the battle. The baflle 5 is constructed as described in a companion a so as to providefsuitable openings to admit the gases from the furnace to the passage" above the bridge wall. 1 supplied with fuel by achain grate 12, andplicat-ion of Davis Sl Jacobus andmyse f Serial No. 542,417,filcd February 7, 1910,

The furnace comprisesa fuel chamber 11 inclosed by sidewalls 14and an arch 15. Embedded. in the side walls 14 are water boxes 16 having their Hlow'er surfaces approximatelyon the gratev line and extmdlng the full length ofthe fuel chamber. The

water cooled surface afforded by so placing the boxes 16 :prevents the formation of a T clinkers on the side walls of'the furnace.

Nippled to the boxes 16 at the back of the furnace is a water box-17 into which the water supply is introduced through box 1'7 "1-h e box-17"-is jdivided-into twopa-rtsby adiaphragm 19 at its center (see Fig. 2)-

providingthereby twoindpendent systems of eirculation'toward the water boxes .16,-

as indicated by :the arrows.v -Water is discharged from'the two side boxes ltj'throu'gh pipes-20. whichbonnect into/the uptake circulation. .A. fourth water Box" 2151M nil seed into at the rear-of the' furnace arch 15 and re- 'ceives circulation from both waterboxes 16 through nipples 22 and discharges through receivesthe upper ends of the roof tubes 8.

headers 6. Pipe 18 receives its water supply structural -work28 which rests on a suitable foundation. 'These side walls 14 are lndependentof the boiler walls and may offizthe boiler walls 30in 'order to insure against any infiltration of air at the junc-' tion 'of the furnace and boiler 'walls. The 114 may. be formed invarious ways and maybe thinner than'is usual-in good pracv143s hown built up of fire-brick having a :coti'ermg- 31 of magnesia or other non-concasing 32. .Theleft-hand wall 14 is shown as built "up of fire-brick backed by an outer be secured in any suitable manner to the; structural work 28 below and'beams 37 "above,.such .structural work, including a extends from ,that point to the ground or floor line. An exterior plate 33 extends up- Iward from the floor line on one side of the boiler and is also attached to beam 37. Between said plate and-the lefit-hand wall 14 is an air chamber 34 which, extends for a part or the full length of the furnace and is common with a space 35 through which air may be' introduced under the grate for combustion, with a result that the radiation fromlthe wall willpass into the air circulat-ing within the closed chamber.

In order toprevent undue movement by expansion of the fire-brick'walls 14., their rectangular. grooves in" which the inclined a vertical direction by narrow grooves 36, all of said grooves extending partially through the fire-brick. The results of expansion are localized by-breaking the con- 'tinuityof 'thesurfaces of the walls 14, and

from box 25 and leads to box 17 which is ,haye upward extensions 14- lying inside tubes 26 are placed, and transversely -or; .in-

'pipe 23 into manifold 24, which manifold The lower ends of the tubes 8'are connected to box 25 whi'ch-is nippld to the downtake walls 14 are tubes 26 connected to manifolds aresupported on the water boxes 16 and on Y i -tice... As shown in Fig. 3, the right hand wall a ductor of heat backed by anexternal metallic metallic casing 32". These casings'32 may plate at about the level of the grate surface,

inner; sides are, divided longitudinally hy' the portions of the walls that are farther from the tire are heated to a less degree and in (ODHLQHQIICQ of this a continuous wall will be less liable to destruction on account of the lesser movement due to expansion. This division of the surfaces of the firebricks prevents the accumulative results of expansion from "afieciiagahe more distant portions of the wall. The water cooling parts of the furnace are embedded as much as is practicable within the brick-work so that the surfaces directly exposed to the heat of the furnace are of as small an area as is possible; thus the boxes 16 and 17 are exposed only on one" sideg thebox '2l i,s; -ex.-... posed on two sides only; and the tubes 26 are exposed only as shown in'Fig. 3.

The furnace walls are relieved entirely of the weight of the boiler walls by the beams 37, thesebeams being supported on columns not shown in the drawing. By making the furnace walls separate it is easy to repair them without affecting the boiler walls. and-byTediIeingfthei-rthickness the repair becomes a matter both simple and inexpensive. As shown in Fig.2, the furnace walls 14 are stopped; short of the beams 37 to prevent any crushing effect from their expansion.

The weight (fifths arch 15 is carried on the structurat-work 28 by means ofeither 'fire brick orinetallic skew backs which skew backs will be held in position bythe usual method of buck-staying across the furnace.

At times in the opera-tion of a furnace equipped with chain grate the fire becomes heavily banked in front of the bridge wall, as shown at 45 ill-Fig.5. Such a bank frequently becomes so thick that the draft through the fire at that point is cut off almostentirely, with the consequence that the bank has a tendency to increase. In order to be able to reduce this bank of incandcscent coal without many means disturbing the other portions of the tire. and without. the use of tire tools, it is desirable to be able to force an extra quantity of air through it. To that end a closed box 38 is introduced into the furnace under the grate in which an air pressure above that under the remaining, portions of the grate may be created. 40 indicates an inlet through i which air may be-forced by a steam jet or other means. The box may have adjustable openings on the top, controlled by slide 4.1, so that only a portion of the fire will be under the influence of thepressure within the box. A damper 39may beattached to an open side of the box sothat it may, by opening slide 41 and damper 39, be. under the same influence of pressure or draft as the remainingportion of the furnace below the grate. This purpose may also be accomiished by the construction shown in Fig. 5 lib-which 2 is the bridge wall, 12 thektoker,

17 the water box, 42 a diaphragm across the stoker between the strands of the chain, which, together with wall 47, forms the inclosed ash pit chamber 43. 4ft represents an opening through which air pressure may be introduced into chamber 43 in excess of that. which exists under the ren'iaining portion of the grate. This is for the purpose of forcing air through a heavy bank of fire represented at 45 which, at times, forms in front of the water box. By means of damper 46 atmospheric pressure. may be admitted to chamber 43, if desired.

' From the. foregoing description it will be seen that, in addition to the advantages alieai'ly'spoken of, by this construction the deterioration of the-furnace walls by crackmg and '(llslnlflgltltlfill will be confined to but each of the two sets of walls is entirely independent from the other.

\Vhat I claim and desire to secure by Letters latent of the United States -is:-'-

1. A boiler furnace having walls consisting of lower sections forming side walls for the fuel chamber, upper sections inclosing the heatingsurfaces, said lower sections being under and extending upwardly to but not supporting the upper sections,'and a support for said upper sections. 2. A boiler furnace having walls consistin; of lower sections forming side walls for the fuel chamber, upper sect-ions inclosing the heating surfaces, said lower sections over-lapping said upper sections but not supporting the same, and a support'for said upper sections.

3. A boiler furnace having walls consisting of lower sections forming side walls for the fuel chamber, upper sections .inclosing the. heating surfaces, said lower sections overlappingsaid upper sections but not supporting same, and protected by water tubes embedded therein. and a support for said upper sections.

4. A boiler furnace having walls consist ing of lower sections forming side walls for the fuel chamber, supports for said sections consisting of structural work terminating at si'ibstantially the grate level, upper s ons inclosing the heating surfaces, said lower sectioiis extending upwardly to but not supporting the upper sections, and a support forsaid upper sections. i

5. A boiler furnace having side walls composed'of water boxes extendingthe length of the fuel chamber beginning at. the grate level, brick-work above the water boxes. and water pipes extending: from approximately the walls of the furnace itself rather than i ,ing longitudinal midway longitudinally oft-he side wi'illsto ward the rear. y

6. A boiler furnace having its brick-work protected by side water boxes beginning approximately at the grate level and extending upwardly,-sai'd bo'xes extending longitudi- ,jnally the length of the fuel chamber, a cross box atithe rear of the fuel chamber connected at its ends to the rear'ends of the side boxes, a water box extending across the fuel chamber atthe rear end of a brick arch and having its ends nippled to the upper sides of'the side boxes, water supply tubes leadin from the downtake circulation of' the boiler into the lowest part of the system of boxes, and circulation tubes extending from the highest points bf this combination of boxes to the uptake circulation of the boiler. p 7

75A boiler furnace having a water box system of protection for the wallsextending from th grate-su'rface upwardly, said system comprisin a cross box at ,therear of the grate, said ox being divided by a lateral partition and having inlet connections at each side of the partition, side boxes extendy of the furnace, each side box being'connected to-the cross box at onev to said boxesandtubesl end and to an outlet connection at its other end, and water supply and delivery pipes secured respectively tofsaid inlet and outlet connections.

S. "A boiler furnace having a chain grate,

side walls beginning at substantially the grate level so that the grate is accessible at its sides beneath said walls, Water boxes set into the side walls immediately 'above the grate and. parallel therewith, and water tubes extending longitudinally of the furnace for the protection of the walls above said boxes, and meansjfor supplying water 9. A boiler furnace having side walls composed' of water tubes embedded in brick work, a metal plate on the outer surface of said brick work, asecond metal plate 'forming an air chamber with the first-named' late, and a connctionbetween said chamer'and'the air inlet to 'thefurnace.

10. A boiler furnace having side walls consisting of fire briqk, a. metal plate on the outer surface of the brick work, a 'second metal plate forming an air'chamber with the first-namedgplate, and structural work to which said metal plates are-attached so that but one thickness of metal can exist between the furnace lining and the atmosphere.

-11. bridge wall, sidewalls, a roof extending from the brid e wall'toward the front, a secondary r00 higherthan the aforesaid roof extending from the front of the upper part of the furnace rearwardly and inclosing a downwardly inclined passageabove 'the first roof.

A boiler furnace having a grate, a

12. A boilersfurnace having a grate, a

bridge wall, side walls, an inclosed downwardly inclined passage above the roof and -an expansion chamberbehind the bridge wall;

13. A boiler furnace-having a grate, side walls beginning at substantially-the grate level, open structural work supporting said side walls so as to make the grate accessible below the side walls, a water box and tubes set into the side walls, an outer protecting 'metalplate, a secondmetal plate surround ing the furnace walls forming an air chamber opening into the conduit leading to the space beneath the grate.

14. In a boiler furnace, furnace Walls comprising a metal casing consisting of plates at substantially the grate level, side plates connected thereto at the outer edges and extending upwardly terminatin at the'top in structural work having a sing e'thickness of nietal between an upward extension-of the furnace brick work and the interior of the furnace, said upward extension projecting beyond the lower edge'of the boiler wall and making an air-tight connection therewith.

15. A boiler furnace having a water box system of protection for the walls extending from the grate surface upwardly, said system comprising across box at the rear of the grate, side boxes extending longitudinally of the furnace, each side box being connected to the cross box at one end and to an outlet connection at its other end, and water su ply and delivery pipes secured respective y to said inlet and outlet connections.

In testimony whereof I have hereunto.

signed by name in the presence of two subscribing witnesses.

'MINOTT W. SEWALL.

Witnesses:

Huon MoDoUoALL, 'Lu'rnnn D. PRATT. 

